thresh
v[I, Tn]
beat out or separate (grain) from husks of wheat, etc using a machine or (esp formerly) an implement held in the hand (用机器)脱粒; (尤指旧时以手持工具)打麦等.
But can we blame those who looked and failed to see what Galileo saw, if we remember that to use a telescope at the limit of its powers calls for long experience and intimate familiarity with one's instrument?